1. Field of the Invention
The present invention relates to a flash memory, and more particularly, to a method, flash memory controller and memory apparatus for accessing a flash memory module.
2. Description of the Prior Art
In order to make a flash memory of high density and large capacity, manufacturers have applied 3D techniques to generate 3D NAND-type flash memories. The entire structure of a 3D NAND-type flash memory is different from that of traditional flash memories. In particular, the shapes and locations of floating gates of the 3D NAND-type flash memory are different, thus introducing some problems when writing/reading data. In some 3D NAND-type flash memories, a plurality of word lines are grouped to a word line group, and a plurality of word line groups may jointly comprise a portion of a control circuit. Hence, when data fails to be written to floating gate transistors of a word line of the word line group, errors may occur on data of floating gate transistors of other word lines. Further, if one word line in a word line group is short circuited or has an open circuit, some errors will occur on floating gate transistors of other word lines in the word line group. Therefore, there is a need for a method to maintain the correctness of data without occupying too much memory space.